LONG BEACH, Calif. (AP) -- The Port of Long Beach, the nation's second-largest cargo container facility, reached a tentative $4.6 billion, 40-year lease with a major Hong Kong-based shipping container line, it was reported Thursday.

Work began earlier on the California harbor's $1.2 billion Middle Harbor Redevelopment, it's largest-ever terminal upgrade and expansion project. It includes a new terminal, upgraded wharfs, a storage area and expanded on-dock rail yard; when completed, it is expected to add 15,000 jobs to the local economy.

The deal with Orient Overseas Container Line, commonly known as OOCL, is expected to be announced Thursday afternoon by Port of Long Beach executive director J. Christopher Lytle.

OOCL will take over the entire 300-acre-plus Middle Harbor site, which will have the capacity to handle three million cargo containers.

"This agreement represents a major endorsement of our vision for the port by one of the leading maritime companies in the world," Lytle told the Los Angeles Times (http://lat.ms/xreIsU ).

OOCL has a fleet of 84 owned and chartered ships and is the world's 12th largest ocean shipping line.

Long Beach, which handles cargo valued at more than $140 billion annually, ranks second to the neighboring Port of Los Angeles in the number of cargo containers handled.

The OOCL announcement comes after a down year for cargo at the port, which lost the Hyundai shipping line and its California United Terminals to Los Angeles rather than wait for completion of the Middle Harbor project.

OOCL chief executive Philip Chow told the Times that the agreement "demonstrates our long-term commitment to the Port of Long Beach as the gateway of choice for North America and solidifies our economic partnership with the region."